Every June 30th, Asteroid Day marks the anniversary of the 1908 Tunguska impact and turns global attention to the science of ...

As the United States prepares to celebrate its 250th anniversary, the history of the solar system tells its own story of ...

The rusty world is full of mysteries—and some of the solar system's most extreme geology. Learn more about Earth's smaller, colder neighbor.

What is Planet Nine, and where is it? The question has fascinated astronomers for years. Scientists believe a massive undiscovered planet may exist in the outer Solar System. Although no telescope has ...

Earth, our home planet, is a world unlike any other. The third planet from the sun, Earth is the only place in the known universe confirmed to host life. With a radius of 3,959 miles, Earth is the ...

The workings of our solar system are roughly the same now as they have been for millions of years. Moons circle their planets, the planets circle the sun, the sun’s magnetic fields and sunspots wax ...

There may soon be three new planets in our solar system. The expansion would be the result of a proposed new definition of what a planet is. The change is controversial, but if adopted by astronomy’s ...